1. Field of the Invention
This invention relates to a digital data transmission system, and in particular, to a binary digital data signal reproducing circuit used at a receiving side in the digital data transmission system.
2. Description of the Prior Art
In the digital data transmission system, data to be transmitted is prepared into a binary digital data signal which comprises a plurality of binary bits of "0" and/or "1", each bit having a predetermined bit length. The digital data signal is sent out to a digital transmission line from a transmitter side after being usually converted to a bipolar signal. At a receiver side, the digital data signal is reproduced from a signal received from the transmitter side through the transmission line.
The signal sent out to the transmission line is distorted during transmission due to affection of noise and/or the transmission property of the transmission line. Therefore, the receiving side has usually a complicated circuit for reliably reproducing the binary digital data signal from the signal received thereat.